1. Field of the Invention
The present invention relates to magneto-optical recording medium having a recording layer of two-layer magnetic film for recording information by radiation of light beam, and recording method using the same.
2. Related Background Art
Research and development of an optical memory element which uses a laser beam to realize a high density and large capacity memory have been rapidly done. Among others, a magneto-optical recording medium is advisable as a rewritable optical memory element.
However, when information recorded on such a magneto-optical recording medium is to be rewritten, the information should be erased and then new information should be recorded. Namely, overwriting of information cannot be attained. For example, when information on a predetermined track on a magneto-optical disk is to be rewritten, the information on the track is erased in one revolution of the disk and then new information is written in the next revolution. As a result, a recording speed is low.
In order to solve the above problem, separate record/reproduce head and erase head are provided in the prior art apparatus, or information is recorded while a magnetic field applied with a continuous laser beam is modulated. However, such an apparatus is of large scale and high cost or cannot attain high speed modulation.
On the other hand, Japanese Laid-Open Patent Application No. 175948/1987 (corresponding to DE-OS No. 3,619,618) discloses magneto-optical recording medium and recording method using the same which enable overwriting like a magnetic recording medium by providing simple magnetic field generation means in the conventional apparatus.
However, since this recording method is novel, there remain many problems to be further studied. One example is study of a magneto-optical recording medium which is better suited to such a recording method.